1988689 has 2 divisors, whose sum is σ = 1988690. Its totient is φ = 1988688.

The previous prime is 1988683. The next prime is 1988699. The reversal of 1988689 is 9868891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1067089 + 921600 = 1033^2 + 960^2 .

It is a cyclic number.

It is not a de Polignac number, because 1988689 - 2⁷ = 1988561 is a prime.

It is a super-3 number, since 3×1988689³ = 23595102555633380307, which contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1988683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994344 + 994345.

It is an arithmetic number, because the mean of its divisors is an integer number (994345).

2^1988689 is an apocalyptic number.

It is an amenable number.

1988689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988689 is an equidigital number, since it uses as much as digits as its factorization.

1988689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 49.

The square root of 1988689 is about 1410.2088497808. The cubic root of 1988689 is about 125.7541397033.

The spelling of 1988689 in words is "one million, nine hundred eighty-eight thousand, six hundred eighty-nine".